Subtyping of herpes simplex virus.

A number of different techniques to be used for the subtyping of herpes simplex virus (HSV) strains were studied. The strains were inoculated on chorio-allantoic membranes of embryonated eggs and on green monkey kidney (GMK) cells in order that the morphology of plaques produced might be observed. They were classified serologically by determination of K-values and inoculated intracerebrally in mice in order that their pathogenicity for mice might be observed. The inhibitory effect of high concentrations of thymidine on the multiplication of the strains in GMK cells cultures and the heat-stability of the virus-induced thymidine kinases were investigated. Rates of inactivation of the strains in the presence of AgNO3 were compared and, finally, the association of focal liver necrosis in intraperitoneally inoculated mice with the results of the serological typing was observed. The results suggested that the liver necrosis test was simple as well as accurate and useful as a screening typing-test. Reliable results were also obtained serologically and by the method demonstrating differences in the heat-stability of viral thymidine kinase. Using the other methods studied, difficulties to obtain clear-cut or reproducible typing results were encountered.